fet140_ta_inclk.c

来自「msp430f14x 系列片内外设的实例代码」· C语言 代码 · 共 48 行

//******************************************************************************
//  MSP-FET430P140 Demo - Timer_A Toggle P1.0, CCR0 upmode ISR, 32kHz INCLK 
//
//  Description; Toggle P1.0 using software and the TA_0 ISR. Timer_A is 
//  configured in an upmode, thus the the timer will overflow when TAR counts 
//  to CCR0. In this example, CCR0 is loaded with 1000-1.
//  Toggle rate = 32768/(2*1000) = 16.384
//  ACLK = TACLK = INCLK = 32768, MCLK = SMCLK = DCO~ 800k 
//  //*An external watch crystal on XIN XOUT is required for ACLK*//	  
//   
//           MSP430F149
//         ---------------
//     /|\|            XIN|-  
//      | |               | 32kHz--
//      --|RST        XOUT|-       |
//        |           P2.1|<-------|
//        |           P1.0|-->LED
//
//  H. Grewal
//  Texas Instruments, Inc
//  Aug 2004
//  Updated for IAR Embedded Workbench Version: 2.21B
//******************************************************************************

#include <msp430x14x.h>

void main(void)
{ 
  WDTCTL = WDTPW + WDTHOLD;             // Stop WDT
  P1DIR |= 0x01;                        // P1.0 output
  P2SEL |= 0x03;
  P2DIR |= 0x01;
  
  CCTL0 = CCIE;                         // CCR0 interrupt enabled
  CCR0 = 1000-1;
  TACTL = TASSEL_3 + MC_1;              // INCLK, upmode

  _BIS_SR(LPM3_bits + GIE);             // Enter LPM3 w/ interrupt
}

// Timer A0 interrupt service routine
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
{
  P1OUT ^= 0x01;                        // Toggle P1.0
}